In fermented beverages like beer and wine, undesirable haze may form during storage due to precipitation/aggregation of haze active (HA) compounds. These compounds may comprise HA polyphenols and HA polypeptides, as well as complex reaction products between them. To increase the colloidal stability of the beverages and enhance their shelf-life, the beverage can be treated to reduce the concentrations of HA compounds, which is often referred to as beer or wine stabilization.
There are several technologies to clarify beer and wine in order to improve the colloidal haze stability. The most common way to remove haze precursors is to add silica hydrogel (SHG) and/or cross-linked polyvinylpyrrolidone particles (polyvinylpolypyrrolidone or PVPP) into non-stabilized beer. Typically dosages are 15-40 g PVPP/hl and ˜50 g SHG/hl (CW Bamforth: J Am Soc Brew Chem 57(3), 81-90, 1999). SHG is intended to reduce haze-active polypeptides and PVPP to reduce polyphenols. Both SHG and PVPP are used in the form of fine particles added to the beverage and afterwards removed by filtration. Traditionally the filter cakes have been discarded, but methods have also been suggested to regenerate the PVPP particles in a separate regeneration installation, as described in e.g. WO 2012/011808. This will however require complex operations and space for additional equipment.
U.S. Pat. No. 6,001,406 describes a method for beverage stabilization using an ion exchanger, in particular a water-insoluble porous hydrophilic matrix to which ion exchanging groups are covalently bound. Such a system has been commercialized by Handtmann Armaturenfabrik GmbH & Co. KG and GE Healthcare Bio-Sciences AB under the name of Combined Stabilization System (CSS), using positively charged crosslinked agarose heads in a packed bed column. The beads remain in the column during both stabilization and regeneration cycles and can be reused for years without any extra handling.
With increased demands on process efficiency and beverage stability, there is however a need for adsorbents with improved binding capacity for HA compounds. U.S. Pat. No. 8,137,559 describes an effort to achieve this with diethylene glycol based ligands on agarose beads, but there is still a need for adsorbents giving improved stabilization and which are able to stabilize higher beverage volumes before regeneration.